A device disclosed in Patent Literature 1 below is one of means for forming an amorphous film on the surface of a substrate by thermal spraying. The device is outlined in FIG. 11, wherein:
A flame including a particulate (powdery) material is sprayed by a thermal spraying gun toward the substrate, while the flame melting the particulate material, and then the particulate material and the flame are cooled by a cooling gas before reaching the substrate.
A skirt for separating the flame from air is provided at a region in a path of the flame sprayed by the thermal spraying gun, where the particulate material melts (roughly, the early half of the flame), and a channel for the cooling gas is integrally structured with and along the skirt.
The thermal spraying gun is the same type as one used for powder flame thermal spraying and the cooling gas is one selected from nitrogen, inert gas, air, liquid-mist mixed gas and other gases.
The conventional device for forming an amorphous film, shown in FIG. 11, has following actions and effects:
The flame is cooled by the cooling gas before reaching the substrate, therefore, it is easy to make the particulate material amorphous, and it is possible to form an amorphous film on the substrate even with a metal having a high melting point and a narrow temperature range of supercooling.
As a high speed flame spraying process is not adopted, the particulate material stays in the flame for a longer time. As a result, it becomes easy to completely melt the particulate material. Also from this point of view, the device enables to form a film even with amorphous alloys, except metallic glass, which have a high melting point and a narrow temperature range of supercooling.
With a compact structure, the device is easy-to-handle and can achieve smooth on-site amorphous film formation.